Mel Strawn’s Theoretical Observations on Solarplate Printmaking

Mel Strawn and his lovely and talented wife, Bernice (“B”), spent three weeks working with Maureen in her studio during last February. Mel and Maureen worked mainly on solar-plate techniques using Dan Welden plates. While Maureen is eminently intuitive, Mel, a lifelong art professor who started making digital prints in 1981, likes some theoretical grounding. So when he got back home to Salida, Colorado, he started thinking about what exactly the two of them had been doing with the solar plates. Here are his preliminary conclusions.

Mel Strawn writes:

I’ve gotten back to printmaking with ink and offer this as an interim finding regarding our exposure questions related to digital inkjet transparencies.

Perhaps I mentioned it before, but the way one sees a grayscale image on screen, the way one sees an inkjet transparency against white paper (with light reflecting back through the transparency and the way the transparency is seen by the light box (or sun) are not the same. Interestingly, an inkjet printer will render the image as seen on screen quite accurately, excelling in detail rendition across the whole range; whites and subtle grays are clearly ‘there’ as are details in the near black, deep tone area. I’m setting aside the difference between acetate transparency material and inkjet transparency material as a separate issue for the moment, though I know Maureen feels strongly about it.

(Maureen’s note: My feeling is that inkjet acetates have a coating on them that they require in order to pick up the ink properly. That coating introduces a slight gray tone into the plate which makes it impossible to achieve a proper white in the print. I prefer to use originals which are printed on a laser printer on perfectly transparent laser acetates .)

The black-to-white images I have been working with should be examined in (say) Photoshop in a ‘curves’ adjustment window. This shows the gamma curve of any image as a straight line reaching diagonally from white to black. In my set up white is at bottom left, black at top right: one can modify the apparent contrast (or density) of the image in any area – essentially by steepening the curve. See the figures here:

The ‘original’ image above. The gamma curve altered to increase the contrast in both the dark and light zones of the image, here more so in the darks than the lights. Absolute blacks and whites stay the same.

In my case, to get a transparency with both lights and darks holding the details and contrasts desired, this is what I’ve come to regarding the way to adjust a transparency that prints O.K. on a digital inkjet printer so that its image will be O.K. when taken through the different and additional steps in solar exposure and printing.

One basically tries for a higher contrast transparency to get a good, wide-range-valued print in solar processing. There are different ways to do essentially this same adjustment in Photoshop.

I have not yet gotten the exact photographer’s data on this (more detailed and technical than I now use) because the book supposedly being worked on has not come out yet. I will pursue that source further.

The other factors we work with, time of exposure, etc. remain a bit intuitive and harder to deal with in theory beyond this: the polymer is hardened by exposure to light. Longer exposure, correspondingly, tends to preserve “whites” – too much, however can burn out delicate light tones (the time factor). Darks: pure blacks should get near zero exposure (denser pigment coverage in the transparency) and distinct light tones (white, light grey, med-light, medium , etc.

The first five steps in a ten-step gray scale) need to be denser in a solar transparency than in a file to become an inkjet print. (I am currently testing to see just how much denser.)

With the longer exposure used typically by Maureen, this makes sense; whites are better hardened and, because of the denser tonality in light grays their gray tonality is protected-and deep darks and black need really dense pigmentation in the transparency to protect them from long exposure burnout.

Critical description: white remained white, blacks are black-while essential light grays are held. The transition between middle gray to black is slightly more abrupt than as seen on a digital screen, close and accepted (for now).

The next day I did a larger print, increasing all times by 10 seconds. Similar results. This was in sun not light box….

So, the quest for perfect theory to match process continues. I think it is good to make clear when we teach others (I do it too, as I did for years in my classes using conventional, pre solar techniques) that as complete a theoretical basis as possible be made available.

“At this stage these findings are based on my observations and tests; they are not “exact”, i.e., calibrated so that they yield a formula to be applied blind. Printmaking is an adventure with all sorts of variables-and that is part of the subjective and very individual challenge.”

So, that’s where I’m at the moment and hope this is maybe helpful. We all know that what is really important (for some mystical human reason) is to do good art and have a good life doing it while we can.

I’m not sure how we got on the subject of ice cream, but I can really relate to the stuff at the bottom of the heap in the garage. A couple of years ago I found a dead kitten while cleaning our pantry/store room. I picked it up and it went “mew.” Maureen recovered it with skim milk and a syringe and as we speak it’s cuddled up in bed with Maureen. Always great to hear from you. Meanwhile, it’s cold as a witches cones here now. Let’s talk about ice cream next spring!